MYMC++ Test 'test_add' fails on Windows but succeeds on Linux

[Issung]

One test in MYMC++ fails on Windows but suceeds on Linux (tested in Ubuntu WSL).
The test is test_memorycard.py test_add,

The test expects this output:

rwx--d----+----       5 2018-04-20 13:37:42 .
-wx--d----+--H-       0 2018-04-21 14:53:00 ..
rwx--d-------H-       4 2018-04-21 14:53:01 BEDATA-SYSTEM
rwx--d----+----       5 2018-04-21 14:53:09 BESCES-50501REZ
rwx-f-----+----      13 2018-04-20 13:37:42 helloworld.txt

But gets this output:

rwx--d----+----       5 2018-04-20 13:37:42 .
-wx--d----+--H-       0 2018-04-21 14:53:00 ..
rwx--d-------H-       4 2018-04-21 14:53:01 BEDATA-SYSTEM
rwx--d----+----       5 2018-04-21 14:53:09 BESCES-50501REZ
rwx-f-----+----      14 2018-04-20 13:37:42 helloworld.txt

The only difference is on the bottom line, in the middle, a 13 is expected but a 14 is produced.
This error isn't due to our own modifications, it happens even in a fresh clone of mymcplus from https://git.sr.ht/~thestr4ng3r/mymcplus.

Powershell pytest output:

Ubuntu WSL output: